An unmanned combat aerial vehicle (UCAV), also known as a combat drone or drone, is an unmanned aerial vehicle (UAV) that is usually armed. Aircraft of this type have no onboard human pilot.[1] Drones are usually under real-time human control, with "the human's role in UCAV system [varying] according to levels of autonomy of UCAV and data communication requirement[s]".[2]

Equipment necessary for a human pilot (such as the cockpit, armor, ejection seat, flight controls, and environmental controls for pressure and oxygen) are not needed, as the operator runs the vehicle from a remote terminal, resulting in a lower weight and size than a manned aircraft. Common UAVs that rely on a single propeller engine are slower and less maneuverable than manned high performance aircraft.[3]

One of the earliest explorations of the concept of the combat drone was by Dr. Lee De Forest, an early inventor of radio devices, and U. A. Sanabria, a TV engineer. They presented their idea in an article in a 1940 publication of Popular Mechanics.[4] The modern military drone as known today was the brainchild of John Stuart Foster Jr., a nuclear physicist and former head of the Lawrence Livermore National Laboratory (then called the Lawrence Radiation Laboratory).[5] In 1971, Foster was a model airplane hobbyist and had the idea this hobby could be applied to building weapons.[5] He drew up plans and by 1973 Defense Advanced Research Projects Agency (DARPA) built two prototypes called "Praeire" and "Calere", they were powered by a modified lawn-mower engine and could stay aloft for two hours while carrying 28-pounds of load.[5]

In the 1973 Yom Kippur War, Israel used unarmed U.S. Ryan Firebee target drones to spur Egypt into firing its entire arsenal of anti-aircraft missiles. This mission was accomplished with no injuries to Israeli pilots, who soon exploited the depleted Egyptian defenses. In the late 1970s and 80s, Israel developed the Scout and the Pioneer, which represented a shift toward the lighter, glider-type model of UAV in use today. Israel pioneered the use of Unmanned aerial vehicles (UAVs) for real-time surveillance, electronic warfare, and decoys.[6][7][8] The images and radar decoying provided by these UAVs helped Israel to completely neutralize the Syrian air defenses in Operation Mole Cricket 19 at the start of the 1982 Lebanon War, resulting in no pilots downed.[9]

In the late 1980s, Iran deployed a drone armed with six RPG-7 rounds in the Iran–Iraq War. This was the first time an armed drone was used in war.[10]

Impressed by Israel's success, the US quickly acquired a number of UAVs, and its Hunter and Pioneer systems are direct derivatives of Israeli models. The first 'UAV war' was the first Gulf War: according to a May 1991 Department of the Navy report: "At least one UAV was airborne at all times during Desert Storm." After the Gulf War successfully demonstrated their utility, global militaries invested widely in the domestic development of combat UAVs.[11]

Various Chinese UCAV concepts have also materialized.[citation needed] WZ-2000, UCAV versions of the Xianglong high altitude are long endurance UAV. Also, dedicated UCAV's Shenyang's Dark Sword (Anjian), and also revealed at Zhuhai 2008 was a model of a stealth strike UCAV with forward swept wings, filling a similar niche to U.S. X-45 called the Warrior Eagle.

Taranis is a British demonstrator programme for unmanned combat air vehicle (UCAV) technology. It is part of the UK's Strategic Unmanned Air Vehicle (Experimental) programme (SUAV[E]). BAE describes Taranis's role in this context as following: "This £124m four year programme is part of the UK Government's Strategic Unmanned Air Vehicle Experiment (SUAVE) and will result in a UCAV demonstrator with fully integrated autonomous systems and low observable features." The Taranis demonstrator will have an MTOW (Maximum Takeoff Weight) of about 8000 kilograms and be of comparable size to the BAE Hawk – making it one of the world's largest UAVs. It will be stealthy, fast, and able to deploy a range of munitions over a number of targets, as well as being capable of defending itself against manned and other unmanned enemy aircraft. The first steel was cut in September 2007 and ground testing started in early 2009. The first flight of the Taranis took place in August 2013 in Woomera, Australia.[18] The demonstrator will have two internal weapons bays. With the inclusion of "full autonomy" the intention is thus for this platform to be able to "think for itself" for a large part of the mission.[citation needed]

Joint Unmanned Combat Air Systems, or J-UCAS, was the name for the joint U.S. Navy/U.S. Air Force unmanned combat air vehicle procurement project. J-UCAS was managed by DARPA, the Defense Advanced Research Projects Agency. In the 2006 Quadrennial Defense Review, the J-UCAS program was terminated.[19] The program would have used stealth technologies and allowed UCAVs to be armed with precision-guided weapons such as Joint Direct Attack Munition (JDAM) or precision miniature munitions, such as the Small-Diameter Bomb, which are used to suppress enemy air defenses. Controllers could have used real-time data sources, including satellites, to plan for and respond to changes on and around the battlefield.

In a New Year 2011 editorial titled "China's Naval Ambitions", The New York Times said "[t]he Pentagon must accelerate efforts to make American naval forces in Asia less vulnerable to Chinese missile threats by giving them the means to project their deterrent power from further offshore. Cutting back purchases of the Navy's DDG-1000 destroyer (with its deficient missile defense system) was a first step. A bigger one would be to reduce the Navy's reliance on short-range manned strike aircraft like the F-18 and the F-35, in favor of the carrier-launched N-UCAS ...."[21]

On 6 January 2011, the DOD announced that this would be one area of additional investment in the 2012 budget request.[22]

The Sagem Sperwer B is a long endurance tactical UAV capable of surveillance and armed combat missions. The Sperwer B improves on its predecessor, the Sperwer A, with twice the payload capacity and twice the endurance, offering a 100 kg payload and 12 hours of sustained flight. It can be outfitted with electro-optic/infrared sensors, electronic and communications intelligence (ELINT/COMINT), synthetic aperture radar (SAR), as well as weapons payloads such as the Rafael Spike-LR anti-tank missile and the Bonus munition from Nexter/BAE Systems Bofors.[23] All ground facilities of the Sperwer A (used by France, Netherlands, Sweden, Greece, Canada and Denmark) are compatible with the Sperwer B.

In 2013, Boeing retrofitted retired multiple Lockheed Martin F-16s (re-designated QF-16) with UAV technology. The company demonstrated combat maneuvers including barrel rolls and a "split S" (where the aircraft turns upside down and flies a descending half-loop, reversing direction) and a perfect center line landing. During the test flight, the plane cruised at 40,000 feet (12,000 m) and reached speeds of Mach 1.47. The aircraft reached 7Gs of acceleration, but was expected to operate at 9Gs. The existing six QF-16s will be augmented in 2015.[26][27]

The international laws of war (such as the Geneva Conventions) govern the conduct of participants in war (and also define combatants). These laws place a burden upon participants to limit civilian deaths and injuries through proper identification of targets and distinction between combatants and non-combatants. The use of completely autonomous weapon systems is problematic, however, because of the difficulty in assigning accountability to a person. Therefore, current designs still incorporate an element of human control (a "man in the loop") – meaning that a ground controller must authorize weapons release.

Concerns also include the human controller's role, because if he is a civilian and not a member of the military (which is quite possible with developmental and highly sophisticated weapons systems) he would be considered a combatant under international law which carries a distinct set of responsibilities and consequences. It is for this reason that the "man in the loop" should ideally be a member of the military that understands and accepts his role as combatant.[39]

Professor Shannon E. French, the director of the Center for Ethics and Excellence at Case Western Reserve University and a former professor at the U.S. Naval Academy, wonders if the PTSD may be rooted in a suspicion that something else was at stake. According to Professor French, the author of the 2003 book The Code of the Warrior (ISBN 0-8476-9756-8):[42]

If [I'm] in the field risking and taking a life, there's a sense that I'm putting skin in the game … I'm taking a risk so it feels more honorable. Someone who kills at a distance—it can make them doubt. Am I truly honorable?

Collateral damage of civilians still takes place with drone combat, although some (like John O. Brennan) have argued that it greatly reduces the likelihood.[44] Although drones enable advance tactical surveillance and up-to-the-minute data, flaws can become apparent.[45] The U.S. drone program in Pakistan has killed several dozen civilians accidentally.[46] An example is the operation in 2010 Feb near Khod, in Urozgan Province, Afghanistan. Over ten civilians in a three-vehicle convoy travelling from Daykundi Province were accidentally killed after a drone crew misidentified the civilians as hostile threats. A force of Bell OH-58 Kiowa helicopters, who were attempting to protect ground troops fighting several kilometers away, fired AGM-114 Hellfire missiles at the vehicles.[47][48]

As of March 2013, the evolution of laws governing drones use continued to be debated.[49][50]

In July 2013, former Pentagon lawyer Jeh Johnson said, on a panel at the Aspen Institute's Security Forum, that he felt an emotional reaction upon reading Nasser al-Awlaki's account of how his 16-year-old grandson was killed by a U.S. drone.[51]

In December 2013, a U.S. drone strike in Radda, capital of Yemen's Bayda province, killed members of a wedding party.[52] The following February, Human Rights Watch published a 28-page report reviewing the strike and its legality, among other things. Titled "A Wedding That Became A Funeral", the report concludes that some (but not necessarily all) of the casualties were civilians, not the intended regional Al-Qaeda targets. The organization demanded US and Yemeni investigations into the attack. In its research, HRW "found no evidence that the individuals taking part in the wedding procession posed an imminent threat to life. In the absence of an armed conflict, killings them would be a violation of international human rights law."[53]

Professor Faisal Kutty of Valparaiso University Law School argues that the use of drones creates "blowback" and undermines core principles of American identity.[54] He cites statistics from the Bureau of Investigative Journalism,[55]Amnesty International, Human Rights Watch and the findings of reports issued by Henry L. Stimson Center[56] and a joint report issued by Stanford Law School and New York University School of Law[57] to make his case.[54] The Stimson report was issued by a bipartisan ten-member panel (co-chaired by John Abizaid, a retired US Army general and former chief of US Central Command and Professor Rosa Brooks from Georgetown). The report unequivocally concluded that "The United States should not conduct a long-term killing program based on secret rationales."[56] Kutty also pointed to an op-ed published by two members of the panel, John B Bellinger III, former legal counsel to the White House National Security Council and Jeff Smith, former legal counsel to the CIA, who wrote arguing that a long-term, secret US drone programme, even if authorised under US law and defensible under international law, may not be consistent with "more basic rule-of-law principles that are at the core of the American identity and that we seek to promote around the world."[54]

As a new weapon, drones are having unforeseen political effects. Some scholars have argued that the extensive use of drones will undermine the popular legitimacy of local governments, which are blamed for permitting the strikes. The case study for this analysis is Yemen, where drone strikes seem to be increasing resentment against the Yemeni government as well as against the U.S.[58]

Some leaders worry about the effect drone warfare will have on soldiers' psychology. Keith Shurtleff, an army chaplain at Fort Jackson, South Carolina, worries "that as war becomes safer and easier, as soldiers are removed from the horrors of war and see the enemy not as humans but as blips on a screen, there is very real danger of losing the deterrent that such horrors provide".[59] Similar worries surfaced when "smart" bombs began to be used extensively in the First Gulf War.

Mark Bowden has disputed this viewpoint saying in his The Atlantic article, "But flying a drone, [the pilot] sees the carnage close-up, in real time—the blood and severed body parts, the arrival of emergency responders, the anguish of friends and family. Often he’s been watching the people he kills for a long time before pulling the trigger. Drone pilots become familiar with their victims. They see them in the ordinary rhythms of their lives—with their wives and friends, with their children. War by remote control turns out to be intimate and disturbing. Pilots are sometimes shaken."[60]

This assessment is corroborated by a sensor operator’s account:

The smoke clears, and there’s pieces of the two guys around the crater. And there’s this guy over here, and he’s missing his right leg above his knee. He’s holding it, and he’s rolling around, and the blood is squirting out of his leg … It took him a long time to die. I just watched him.

In February 2013, Fairleigh Dickinson University's PublicMind poll conducted a study to measure U.S. public opinion on the use of drones. The study was conducted nationwide, and it asked registered voters whether they "approve or disapprove of the U.S. Military using drones to carry out attacks abroad on people and other targets deemed a threat to the U.S.?" The results showed that three in every four (75%) of voters approved of the U.S. Military using drones to carry out attacks, while (13%) disapproved.[63]

Another poll in February 2013 conducted by the Huffington Post was more equivocal: 56% of Americans support using drones to kill "high level terrorists," 13% support using drones to kill "anyone associated with terrorists," 16% thought no one should be killed with drones, and 15% were not sure.[64]

Outside America, support for drones is far lower. A Pew Research study of 20 countries in 2012 found widespread international opposition to US drone killings.[65]